30行，金额转人民币大写的代码

本文转自：http://www.cnblogs.com/stephen-wang/p/3155958.html

金额转人民币大写是一种常见的要求，但是这一看似简单的要求，实现起来却并不容易。

前不久，我被问到了这样一道题，当时写了个算法，昨天晚上又和BJDP的人们讨论了一下，觉得很有必要把这个算法写下来。

总共36行，去掉空行还不到30行，就不多啰嗦解释了。

public class ChineseCurrencyConverter {
 
     private static final String[] UNITS = {"亿","仟万","佰万","拾万","万","仟","佰","拾","" };
     private static final String[] CHINESE_NUMBER = {"零","壹","贰","叁","肆","伍","陆","柒","捌","玖"};
 
     public static String convert(long yuan) {
 
         if (yuan >= 1e9 || yuan < 0) {
             return "这个数字超出解析范围了";
         }
         String amount = String.valueOf(yuan);
         int len = amount.length();
         int unitsLen = UNITS.length;
 
         String chineseCurrency = "";
         for (int i = len - 1; i >= 0; i--) {
             chineseCurrency = number(amount.charAt(i)) + unit(amount.charAt(i), unitsLen - len + i) +chineseCurrency;
         }
 
         chineseCurrency = chineseCurrency.replaceAll("零+","零");
         chineseCurrency =  chineseCurrency + "元整";
         chineseCurrency = chineseCurrency.replaceAll("零元","元");
         return chineseCurrency;
     }
 
     private static String number(char number) {
          return CHINESE_NUMBER[Integer.parseInt(String.valueOf(number))];
     }
 
     private static String unit(char number, int pos) {
         if(number == '0') {
             return "";
         }
         return UNITS[pos];
     }
 }

下面是一些用来测试的代码：

public class TestConverter  {
 
      public static void main(String[] args) {
          System.out.println(ChineseCurrencyConverter.convert(100));
          System.out.println(ChineseCurrencyConverter.convert(130));
          System.out.println(ChineseCurrencyConverter.convert(102));
          System.out.println(ChineseCurrencyConverter.convert(124));
          System.out.println(ChineseCurrencyConverter.convert(1000));
          System.out.println(ChineseCurrencyConverter.convert(10000));
          System.out.println(ChineseCurrencyConverter.convert(100000));
          System.out.println(ChineseCurrencyConverter.convert(1000000));
          System.out.println(ChineseCurrencyConverter.convert(10000000));
          System.out.println(ChineseCurrencyConverter.convert(10000000));
          System.out.println(ChineseCurrencyConverter.convert(100000000));
          System.out.println(ChineseCurrencyConverter.convert(1000000000));
          System.out.println(ChineseCurrencyConverter.convert(1002));
          System.out.println(ChineseCurrencyConverter.convert(1020));
          System.out.println(ChineseCurrencyConverter.convert(1200));
          System.out.println(ChineseCurrencyConverter.convert(10003));
          System.out.println(ChineseCurrencyConverter.convert(10030));
          System.out.println(ChineseCurrencyConverter.convert(10033));
          System.out.println(ChineseCurrencyConverter.convert(10330));
          System.out.println(ChineseCurrencyConverter.convert(13030));
          System.out.println(ChineseCurrencyConverter.convert(100030));
          System.out.println(ChineseCurrencyConverter.convert(100003));
          System.out.println(ChineseCurrencyConverter.convert(100300));
          System.out.println(ChineseCurrencyConverter.convert(103000));
          System.out.println(ChineseCurrencyConverter.convert(100303));
          System.out.println(ChineseCurrencyConverter.convert(1000004));
          System.out.println(ChineseCurrencyConverter.convert(10000005));
          System.out.println(ChineseCurrencyConverter.convert(10000006));
          System.out.println(ChineseCurrencyConverter.convert(100000007));
          System.out.println(ChineseCurrencyConverter.convert(1000000008));
 
      }
 }

这些数字测试的结果还都正确。

这里没有处理角和分，留给有想法的同学去尝试一下吧。